here's a suggestion, Daenerys in the evening goes to her room to rest, can choose to leave the light on or not, if she leaves it on, she will see Jorah or Viserys entering the tent (in this case maybe she could be forced by Viserys who in turn could be killed by Drogo or asked for more pleasure by Jorah, again another possible choice), if not she will be fooled in thinking is Drogo and be aware only when is too late or even be unaware the whole time...possible bad ending if Drogo should come in, but would be better if not.